General  Specifications 


Steel  Roofs  and  Buildings 


FOURTH  REVISED  EDITION. 
With  Tables. 


THE  UNIVERSITY 


OF  ILLINOIS 
LIBRARY 


GENERAL   SP%GIFI6kTI0NS  FOR  STEEL 
ROOFS  AND  BUILDINGS. 

Charles  Evan  Fowler,  M.  Am.  Soc.  C.  E. 
Fourth  Revised  Edition 
1899. 

GENERAL  DESCRIPTION. 

1.  The  structure  shall  be  of  the  general  outline  and  dimen-  diagram, 
sions  shown  on  the  attached  diagram,  which  gives  the  principal 
dimensions  and  all  the  principal  data.    (2,  72,) 

2.  The  sizes  and  sections  of  all  members,  together  with  the 
strains  which  come  upon  them,  shall  be  marked  in  their 
proper  places  upon  a  strain  sheet,  artd  submitted  with  proposal. 
(i>  72.) 

3.  The  height  of  the  building  shall  mean  the  distance  from  clearances, 
top  of  masonry  to  under  side  of  bottom  chord  of  truss.  The 

width  and  length  of  building  shall  mean  the  extreme  distance 
out  to  out  of  framing  or  sheeting. 

4.  The  pitch  of  roof  shall  generally  be  one  fourth.  (6.) 

LOADS. 

The  trusses  shall  be  figured  to  carry  the  following  loads: 


5.  Snow  loads. 

PITCH  OF  ROOF. 

LOCATION. 

1-2 

1-3 

i-4 

i-5 

1-6 

Southern  States  and  Pacific  Slope  . 

0 

0 

0 

0 

0 

0 

7 

15 

22 

30 

Rocky  Mountain  States  .... 

0 

10 

20 

27 

35 

0 

10 

20 

35 

45 

0 

12 

25 

37 

50 

Snow  Load. 


Pounds  per  hor.  sq.  foot. 
6.    The  wind  pressure  on  trusses  in  pounds  per  square  foot  wind  Load, 
shall  be  taken  from  the  following  table: 


Pitch 

Vertical 

Horizontal 

Normal. 

i-2=45°oo' 

19 

19 

27 

i^3  =  33°4i/ 

17 

12 

22 

1 -4=26°  34' 

15 

8 

18 

i-5  =  2i°48' 

13 

6 

15 

i-6=i8°26' 

11 

4 

13 

(7.) 

7.  The  sides  and  ends  of  buildings  shall  be  figured  for  a 
uniformly  distributed  wind  load  of  20  pounds  per  square  foot 
of  exposed  surtace  when  20  feet  or  less  to  the  eaves;  30 
pounds  per  square  foot  of  exposed  surface  when  60  feet  to  the 
eaves,  and  proportionately  for  intermediate  heights.  (6.) 


47834 


Weight  of  cov-   8.    The  weight  of  covering  may  be  taken  as  .follows:  Cor- 
ermg     rugated  iron  laid,  black  and  painted,  per  square  foot: 
No.  27      26      24      22       20       18  16 

.90     1. 00     1.30   1.60     1.90    2.60    3.30  pounds. 
For  galvanized  iron  add  0.2  pounds  per  square  foot  to  above 
figures. 

Slate  shall  be  taken  at  a  weight  of  7  pounds  per  square  foot 
for  3-16"  .slate  6"  x  12",  and  8.25  pounds  .per  square  foot  for 
3-16"  slate  I2"x  24",  and  proportionately  for  other  sizes. 

Sheeting  of  dry  pine  boards  at  three  pounds  per'  foot  board 
measure. 

Plastered  ceiling  hung  below  at  not  less  than  10  pounds  per 
square  foot. 

The  exact  weight  of  purlins  shall  be  calculated. 

9.  The  weight  of  Fink  roof  trusses  up  to  200  feet  span 
may  be  calculated  by  the  following  formulas,  for  preliminary  value. 

w=.o6  S+.6,  for  heavy  loads. 
w=.04  S+.4,  for  light  loads.       (40,  45.) 
s=span  in  feet.     w=weight  per  hor.  sq.  ft.  in  pounds. 

10.  Mill  buildings,  or  any  that  are  subject  to  corrosive  action 
of  gases,  shall  have  all  the  above  loads  increased  25  per  cent. 

11.  Buildings  or  parts  of  buildings  subject  to  strains  from 
machinery  or  other  loads  not  mentioned,  shall  have  the  proper 
allowance  made. 

12.  No  roof  shall,  however,  be  calculated  for  a  less  load  than 
30  pounds  per  horizontal  square  foot. 


Weight  of 
Trusses 


Increase  of 
Loads. 


Minimum 
Load. 


Tension  only.      j  3 , 


Compression 
only. 


Flanges. 


'Combined. 


UNIT  STRAINS. 

Iron. 

Shapes,  net  section  .... 

Bars  14000 

Bottom  flanges  of  rolled  beams 
Laterals  of  angles,  net  section  . 
Laterals  of  bar  18000 


Soft-Medium. 

Steel 
1500O 
17000 
15000 
20000 


(57) 


(57) 
WO 

/ 

12500—500— 
r 

/—length  in  feet  c.  to  c.  of  connections. 
r=  least  radius  of  gyration  in  inches.  (59) 
Top  flanges  of  built  girders  shall  have  the  same  gross 
area  as  tension  flanges.  (24) 

16.  Members  subject  to  transverse  loading  in  addition  to 
direct  strain,  such  as  rafters,  and  posts  having  knee  braces  con- 
nected to  them,  shall  be  considered  as  fixed  at  the  ends  in  rivit- 
ed  work,  and  shall  be  proportioned  by  the  following  formula?,  and 
the  unit  strain  in  extreme  fibre  shall  not  exceed  for  soft  medium 
steel:  15000 


14.    Flat  ends  and  fixed  ends 


IS 


3 


Mrt  P 

S  =           +   ■ 

I  A  (52,  62.) 

5  =  Strain  per  square  inch  in  extreme  fibre. 
M  —  Moment  of  transverse  force  in  inch  pounds, 
n  =  Distance  center  of  gravity  to  top  or  bottom  of  final  section 

in  inches. 


I  = 

Final  moment  of  inertia. 

p  = 

Direct  load. 

A 

Final  area. 

Soft-Medium 

Soft  Steel. 

Steel. 

17. 

(57) 

7000 

18. 

On  dia.  of  pins  and  rivet  holes  20000 

20000 

(57) 

19. 

Extreme  fibre  of  pins   .    .  . 

25000 

Extreme  fibre  of  purlins    .  . 

15000 

(49) 

20. 

Lateral  connections  will  have  25  per 

cent  greater 

unit 

Shearing. 

Bearing. 
Bending. 

Laterals. 


strains  than  above. 

21.  Bolts  may  be  used  for  field  connections  at  two-thirds  of  Bolts* 
rivet  values.       (17,  18.) 

TIMBER  PURLINS 


22.  In  purlins  of  yellow  pine,  southern  pine  or  white  oak, 
the  extreme  fibre  strain  shall  not  exceed  1200  lbs.  sq.  in.  (50) 


Timber. 


PLATE  GIRDERS. 

0  23.    The  length  of  span  shall  be  considered  as  the  distance  Girder5- 
^  from,  center  to  center  of  end  bearings  when  girders  rest  on 

u  bottom  flange,  and  from  end  to  end  when  fastened  between 

1  columns  by  connection  angles. 

£     24.    The  compression  flanges  shall  be  stayed  transversely  Flanges. 
^  when  their  length 'is  more  than  thirty  times  their  width.  (15) 
One-sixth  of  the  web  shall  be  included  as  flange  area,  provided 
proper  horizontal  splices  are  made  at  web  joints. 

25.  All  web  plates  shall  be  stiffened  at  the  inner  and  outer  stiffened, 
edges  of  the  end  bearings  and  at  all  points  of  local  concentrated 
loading. 

Intermediate  stiffeners  shall  be  used  provided  the  shearing 
strain  per  square  inch  exceeds  that  given  by  the  formula: 
15000 

d2  d—  Clear  dist.  between  flange  angles  in  inches. 

1  -1   Thickness  of  web  in  inches. 

3000/2 

CORRUGATED  IRON  COVERING. 

26.  Corrugated  iron  shall  generally  be  of  2><  inch  corruga-  covering, 
tions,  and  the  gage  in  U.  S.  standard  shall  be  shown  on  strain 
sheet. 


4 


Valleys 


Ridges 


Fastenings 


louvres 


Windows 


Skylights 


27.  The  span  or  distance  center  to  center  of  roof  purlins 
shall  not  exceed  that  given  in  the  following  table: 


27  gage 
26  gage 
24  gage 
22  gage 


2'- 
2'— 6" 
3'— o" 
4'— 0" 


20  gage 
18  gage 
16  gage 


4'— 6" 
5'— o" 
5'— 6" 


(48) 


shall  be  laid  with  one  corrugation 
four  inches  end  lap,  generally  with 


Finish  Augi 


Ventilators 


28.  All  corrugated  iron 
side  lap,  and  not  less  than 
six  inches  end  lap.  (32) 

29.  All  valleys  or  junctions  shall  have  flashing  extending  at 
least  12  inches  under  the  corrugated  iron, or  12  inches  above  line 
where  water  will  stand.  (35,  36.) 

30.  All  ridges  shall  have  roll  cap  securely  fastened  over  the 
corrugated  iron. 

31.  Corrugated  iron  shall  preferably  be  secured  to  the  purlin 
by  galvanized  straps  of  not  less  than  five-eighths  of  an  inch  wide 
by  No.  18  gage;  these  shall  pass  completely  around  the  purlin, 
and  have  each  end  riveted  to  the  sheet.  There  shall  be  at  least 
two  fastenings  on  each  purlin  for  each  sheet. 

32.  The  side  laps  shall  be  riveted  with  six  pound  rivets  not 
more  than  six  inches  apart.  (28.) 

33.  At  the  gable  ends  the  corrugated  iron  shall  be  securely 
fastened  down  on  the  roof,  to  a  finish  angle  or  channel,  connect- 
ed to  the  end  of  the  roof  purlins. 

VENTILATORS  AND  LOUVRES. 

34.  Ventilators  shall  be  provided  and  located  so  as  to  properly 
ventilate  the  building.  They  shall  have  a  net  area  of  openings 
for  each  100  square  feet  of  floor  surface  of  not  less  than  one- 
half  a  square  foot  for  machine  shops,  of  not.  less  than  five  square 
feet  for  miil  buildings  and  not  less  than  seven  square  feet  for 
forge  shops. 

Louvres  shall  be  provided  in  ventilators,  if  necessary,  of  such 
form  as  to  prevent  the  blowing  in  of  snow  or  storm  water,  and  of 
a  stiff  enough  section  not  to  sag  below  hoizontal  and  appear  un- 
sightly. They  shall  be  not  less  than  No.  16  gage  galvanized 
for  flat  louvres*  and  No.  20  gage  galvanized  for  corrugated  lou- 
vres. 

LIGHTING. 

35.  Windows  shall  be  provided  in  the  sides  and  clearstory  or 
ventilator  of  a  surface  equal  to  not  less  than  10  per  cent  of  the 
entire  exterior  surface  of  the  buildings,  in  mill  buildings,  and  of 
not  less  than  20  per  cent  in  machine  shops  or  similiar  build- 
ings. (29) 

36.  At  least  half  of  the  lighting  specified  shall  preferably 
be  in  the  form  of  skylights  of  some  form  of  construction  which 
shall  entirely  prohibit  leaking.  (29) 


DETAILS  OF  CONSTRUCTION. 

37.  All  tension  members  shall  preferably  be  composed  of  Tension  Mem- 
angles  or  shapes  with  the  object  of  stiffness.  bers* 

38.  All  joints  shall  have  full  splices  and  not  rely  on  gussets. 

(650 

39.  All  main  members  shall  preferably  be  made  of  two  angles, 
back  to  back,  two  angles  and  one  plate,  or  four  angles  laced.  (67.) 

40.  Secondary  members  shall  preferably  be  made  of  sym- 
metrical sections. 

41.  Long  laterals  or  sway  rods  may  be  made  of  bar,  with 
sleeve  nut  adjustment,  to  facilitate  erection. 

42.  Members  having  such  a  length  as  to  cause  them  to  sag 
shall  be  held  up  by  sag  ties  of  angles,  properly  spaced. 

43.  Rafters  shall  preferably  be  made  of  two  angles,  two Com^^ib011 
angles  and  one  plate,  or  of  such  form  as  to  allow  of  easy  connec-        era  ers* 
tion  for  web  members.  (65.) 

44.  All  other  compression  members,'  except  sub-struts,  shall 
be  composed  of  sections  symmetrically  disposed.  (65.) 

45.  Sub-struts  shall  preferably  be  made  of  symmetrical  sec- 
tions. 

46.  Tjie  trusses  shall  be  spaced,  if  possible,  at  such  distances  PurliQ3* 
apart  as  to  allow  of  single  pieces  of  shape  iron  being  used  for 
purlins,  trussed  purlins  being  avoided,  if  possible.     Purlins  shall 
preferably  be  composed  of  single  angles,  with  the  long  leg  verti- 
cal and  the  back  toward  the  peak  of  the  roof. 

47.  Purlins  shall  be  attached  to  the  rafters  or  columns  by 
clips,  with  at  least  two  rivets  in  rafter  and  two  holes  for  each  end 
of  each  purlin. 

48.  Roof  purlins  shall  be  spaced  at  distances  apart  not  to  ex- 
ceed the  span  given  under  the  head  of  Corrugated  Iron.  (27.) 

49.  Purlins  extending  in  one  piece  over  two  or  more  panels, 
laid  to  break  joint,  and  riveted  at  ends,  may  be  figured  as  con- 
tinuous. 

50.  Timber  purlins,  if  used,  shall  be  attached  in  the  same 
manner  as  steel  purlins. 

51.  Sway  bracing  shall  be  introduced  at  such  points  as  is  sway  Bracing- 
necessary  to  insure  ease  of  erection  and  sufficient  transverse  and 
longitudinal  strength.  (41.) 

52.  All  such  strains  shall  preferably  be  carried  to  the  founda- 
tion direct,  but  may  be  accounted  for  by  bending  in  the  columns. 

(62.) 

53.  Bed  plates  shall  never  be  less  thar  one-half  inch  in Bed  Plates, 
thickness,  and  shall  be  of  sufficient  thickness  and  size  so  that 

the  pressure  on  masonry  will  not  exceed  300  pounds  per  square 
inch.  Trusses  over  75  feet  span  on  walls  or  masonry  shall  have 
expansion  rollers  if  necessary.  (54.) 


6 


Anchor  Bolts. 


Punching. 


Punching-  and 
Reaming-. 


Effective 
Diameter  of 
Rivets. 


Pitch  of 
Rivets. 


Length  of 
Compression 
Members. 

Tie  Plates. 


Lacing-  Bars. 


Bending". 


Upset  Rods. 


Variation  in 
Weight 


54.  Each  bearing  plate  shall  be  provided  with  tv/o  anchor 
bolts  of  not  less  than  three-fourths  of  an  inch  in  diameter,  either 
built  into  the  masonry  or  extending  far  enough  into  the  masonry 
to  make  them  effective.  (53.) 

55.  The  diameter  of  the  punch  shall  not  exceed  the  diamter 
of  the  rivet,  nor  the  diameter  of  the  die  exceed  the  diameter  of 
the  punch  by  more  than  one-sixteenth  of  an  inch.  (56.) 

56.  All  rivet  holes  in  steel  may  be  punched,  and  in  case  holes 
do  not  match  in  assembled  members  they  shall  be  reamed  out 
with  power  reamers.  (71.) 

57.  The  effective  diameter  of  the  driven  rivet  shall  be  as- 
sumed the  same  as  before  driving,  and  in  making  deductions  for 
rivet  holes  in  tension  members,  the  hole  will  be  assumed  one 
eighth  of  an  inch  larger  than  the  undriven  rivet.  (13,17.) 

58.  The  pitch  of  rivets  shall  not  exceed  twenty  times  the 
thickness  of  the  plate  in  the  line  of  strain,  nor  forty  times  the 
thickness  at  right  angles  to  the  line  of  strain.  It  shall  never  be 
less  than  three  diameters-of  the  rivet.  At  the  ends  of  compres- 
sion members  it  shall  not  exceed  four  diameters  of  the  rivet  for  a 
length  equal  to  the  width  of  the  members. 

59.  No  compression  member  shall  have  a  length  exceeding 
fifty  times  its  least  width,  unless  its  unit   strain  is  reduced 
accordingly.  (14.) 

60.  Laced  compression  members  shall  be  stayed  at  the  ends 
by  batten  plates  having  a  length  not  less  than  the  depth  of  the 
member. 

61.  The  sizes  of  lacing  bars  shall  not  be  less  than  that  given 
in  the  following  table,  when  the  distance  between  the  gage 


lines  is- 


6"  or  less  than 
8"  or  less  than 

ro"  or  less  than 

12 

16 


(62.) 


10" 
12" 

"  or  less  than  16" 
"  or  less  than  20" 


20"  or  less  than  24"  . 
24"  or  above  of  angles, 


i 
1 

1 

2" 
2  1 
2  1-2 


1-4"  x  1-4' 


1-2' 
3-4' 


4"  x 


x  1-4" 
x  5-16" 
x  3-8" 

7-16" 
x  1-2" 


They  shall  generally  be  inclined  at  45  degress  to  the  axis  of 
the  member,  but  shall  not  be  spaced  so  as  to  reduce  the  strength 
of  the  member  as  a  whole. 

62.  Where  laced  members  are  subjected  to  bending,  the  size 
of  lacing  bars  or  angles  shall  be  calculated  or  a  solid  web  plate 
used.    (13,  14,  61.) 

63.  All  rods  having  screwends  shall  be  upset  to  standard  size, 
or  have  due  allowance  made.  #■ 

64.  No.  metal  of  less  thickness  than  %.  inch  shall  be  used, 
except  as  fillers,  and  no  angles  of  less  than  2  inch  leg.  A  varia- 
tion of  3  per  cent  shall  be  allowable  in  the  weight  or  cross  sec- 
tion of  material. 


7 


WORKMANSHIP. 

65.  All  workmanship  shall  be  first  class  in  every  particular.  j££l**d  Sttr* 
All  abutting  surfaces  of  compression  members,  except  where 

the  joints  are  fully  spliced,  must  be  planed  to  even  bearing 
so  as  to  give  close  contact  throughout.  (38.) 

66.  All  planed  or  turned  surfaces  left  exposed  must  be  pro- 
tected by  white  lead  and  tallow.  (89) 

67.  Rivet  holes  for  splices  must  be  so  accurately  spaced  that  Rivete 
the  holes  will,  come  exactly  opposite  when  the  members  are 
brought  into  position  for  driving  rivets,  or  else  reamed  out. 

(38,  70,71.) 

68.  Rivets  must  completely  fill  the  holes  and  have  full  heads 
concentric  with  the  rivet  holes.  They  shall  have  full  contact  with 
the  surface,  or  be  countersunk  when  so  required,  and  shall  be 
machine  driven  when  possible.  Rivets  must  not  be  used  in 
direct  tension. 

69.  Built  members  when  finished  must  be  free  from  twists, 
open  joints  or  other  defects.  (65.) 

70.  Drift  pins  must  only  be  used  for  bringing  the  pieces  to-  Driuin£« 
gether,  and  they  must  not  be  driven  so  hard  as  to  distort  the 
metal.  (71.) 

71.  When  holes  need  enlarging,    it  must  be  done  by  ream-  Reaming, 
ing  and  not  by  drifting.  (70.) 

72.  The  decision  of  the  engineer  or  architect  shall  control  as  Drawings  and 
as  to  the  interpretation  of  the  drawings  and  specifications  during  sPecificat'ns- 
the  progress  of  the  work.    But   this    shall  not  deprive  the 
contractor  of  right  of  redress  after  work  is  completed,  if  the  de- 
cision shall  be  proven  wrong.    (1,  91,95.) 


QUALITY  OF  MATERIAL. 

WROUGHT  IRON 

73.  All  wrought  iron  must  be  tough,  ductile,  fibrous  and  of  cha™cter  attd 
uniform  quality.    Finished    bars  must  be  thoroughly  welded  Fimsh* 
during  the  rolling,  and  be  straight,  smooth  and  free  from  in- 
jurious seams,  blisters,  buckles,  cracks  or  imperfect  edges. 

74.  No  one  process  of  manufacture  is  preferred  over  another,  Manufacture, 
provided  the  material  complies  with  this  specification. 

75.  For  tension  tests  the  test  piece  shall  have  as  near  one- standard  Test 
half  square  inch  of  sectional  area  as  possible,  and  a  length  of  at  Pieces> 
least  8  inches  with  uniform  section,  for  determining  the  elongation. 

76.  The  elastic  limit  shall  be  not  less  than  26,000  pounds  per  Elastic  Limit 
square  inch  for  all  classes  of  iron. 

77.  Standard  test  pieces  from  iron  having  a  section  of  4%  Teos:-on  Iron 
square  inches  or  less  shall  show  an  ultimate  strength  of  not  less 

than  50,000  pounds  per  square  inch  and  an  elongation  in  8  inches 
of  not  less  than  18  per  cent. 


8 

78.  Standard  test  pieces  from  bars  of  more  than  4^  square 
inches  section  will  be  allowed  a  reduction  of  500  pounds  for 
each  additional  square  inch  of  section,  provided  the  ultimate 
strength  does  not  fall  below  48,000  pounds  or  the  elongation  in 
8  inches  below  15  per  cent. 

79.  All  iron  for  tension  members  must  bend  cold  through 
90  degrees  to  a  curve  whose  diameter  is  not  over  twice  the 
thickness  of  the  piece,  without  cracking. 

80.  Not  less  than  one  sample  out  of  three  shall  bend  cold  to 
this  curve  through  180  degrees,  without  cracking. 

81.  When  nicked  on  one  side  and  bent  by  a  blow  from  a 
sledge,  the  fracture  must  be  wholly  fibrous. 


STEEL. 

Mamsfacture.     g2.    Steel  made  either  by  the  Bessemer  or  Open  Hearth  pro- 
cess of  manufacture  shall  be  acceptable. 

SpieceSrd  TeSt   83'    Test  P^ces  for  tension  and  bending  tests  shall  have  as 
1  c  't       near  one-half  square  inch  of  sectional  area  as  possible  and  a 
length  of  at  least  8  inches  with  uniform  section,  for  determiming 
elongation. 

84.    One  test  piece  for  tension  and  one  for  bending  are  to  be 
taken  from  each  heat  or  blow  of  finished  material. 
Finish..  85.    Finished  bars  must  be  free  from  flaws,  cracks  or  injurious 

seams  and  have  a  first-class  finish. 
Grades  gof^     g£.    Steel  of  soft  and  soft-medium  grades  only  are  to  be  used, 
'  the  soft  steel  for  rivets  and  offset  or  bent  angles  or  plates,  and 
soft-medium  for  all  other  parts  where    iron   is  not  optional. 
Phosphorus   The  phosphorus  shall  never  exceed  in  any  steel  0.08  per  cent., 
aadLimu  hnt  nor  the  sulphur  0.04  per  cent.  (56.) 

soft  steei.  87.  Standard  test  pieces  of  finished  material  shall  have  an 
ultimate  strength  of  from  50,000  to  60,000  pounds  per  square 
inch;  an  elastic  limit  of  one-half  the  ultimate  strength;  an 
elongation  in  8  inches  of  not  less  than  25  per  cent;  and  a 
reduction  of  area  at  fracture  of  not  less  than  50  per  cent. 
Samples  to  bend  cold  180  degrees  flat  on  itself,  without  sign  of 
fracture  on  the  outside  bent  portion. 

soft-Medium  88.  Standard  test  pieces  of  finished  material  shall  have  an 
steei.  ultimate  strength  of  from  55,000  to  65,000  pounds  per  square 
inch;  elastic  limit  not  less  than  one-half  the  ultimate  strength; 
an  elongation  in  8  inches  of  not  less  than  25  per  cent.;  and  a 
reduction  of  area  at  fracture  of  not  less  than  50  per  cent.  Samples 
to  bend  cold  180  degrees  to  a  diameter  equal  to  the  thickness  of 
the  sample  without  crack  or  flaw  on  fhe  outside  of  the  bent 
portion. 

PAINTING. 

Painting.  89.  All  iron  or  steel  framing  and  all  corrugated  iron,  unless 
galvanized,  shall  have  one  coat  of  pure  lead  paint  before  leaving 
the   shop;  all    surfaces    in    contact  shall  have   one  heavy 


9 

coat  of  pure  lead  paint  before  assembling,  and  all  planed  or 
turned  surfaces  shall  be  coated  with  white  lead  and  tallow  (66.) 

90.  Parts  difficult  of  access  after  erectiion  shall  have  two 
coats  of  pure  lead  paint  at  the  shop. 

91.  After  erection  all  the  work  except  galvanized  iron  shall 
receive  one  coat  of  pure  lead  paint  of  such  shade  as  the  engineer 
or  architect  may  select,  and  it  shall  be  thoroughly  and  evenly 
applied.  (72,95-) 

ERECTION. 

92.  The  contractor  will  furnish  all  tools,  derricks  or  staging  Erection* 
and  material  of  every  description  for  the  erection  of  the  whole  or 

such  portions  of  the  work  as  are  included  in  the  contract,  and 
remove  the  same  when  the  work  is  completed,  leaving  the  prem- 
ises as  free  from  rubbish  or  obstruction  as  when  the  erection  was 
commenced. 

93.  The  contractor  shall  assume  all  risks  from  storms  or  acci- 
dents to  the  work,  unless  caused  by  the  negligence  or  interfer- 
ence of  the  owner  or  his  employees;  also  all  damage  to  persons 
and  properties  and  casualties  of  every  description,  until  the 
final  acceptance  of  the  completed  structure. 

94.  The  contractor  shall  comply  with  all  ordinances  or  reg- 
ulations of  the  authorities  having  jurisdiction  over  the  premises  or 
abutting  premises. 

95.  The  erection  is  to  be  carried  on  subject  to  the  approval 
and  inspection  of  the  engineer  or  architect,  and  it  is  to  be  com- 
pleted to  his  satisfaction  and  in  full  accordance  with  the 
contract.  (72,91.) 


s=span.  h= height.  P=  panel  load.  n  =  jj=  pltxch 
-{-compression.  — tension.  Strain  in  member  =  P x coefficient. 
Load  on  wall  or  column  =  Reaction-}-o.5P. 


PRATT    TRUSS,    EIGHT  PANELS. 


Member 

n~4 

n=$ 

General  Formulae. 

Ba-Cb 

6.31 

7.83 

9.42 

+  4 

XP 

Dd 

5.41 

6.71 

8.08 

+  i.$cW 

+  4 

XP 

Ef 

4.51 

5.59 

6.73 

+  1.25  W  +  4 

XP 

La 

5.25 

7.00 

8.75 

— 1,75  n 

XP 

Lc 

4.50 

6.00 

7.50 

— 1.50  n 

XP 

Le 

3.75 

5.00 

6.25 

— 1.25  n 

XP 

Lg 

3.00 

4.00 

5.00 

— 1. 00  n 

XP 

ab 

1. 00 

1. 00 

1. 00 

+  1.00 

XP 

cd 

1.50 

1.50 

1.50 

+  1.50 

XP 

ef 

2.00 

2.00 

2.00 

-f-2.00 

XP 

be 

1.25 

1.41 

1.60 

 0.2$y/fjZ. 

-f-16 

XP 

de 

1.68 

1.80 

1.95 

—0.2Wtfl+  36 

XP 

fg 

2.14 

2.24 

2.36 

—0.25^+64 

XP 

PRATT  TRUSS,  FOUR  PANELS.  n 


Member 

te=3 

72  =  4 

?z=5 

General  Formulae. 

O  ^  { —  U 

Ba-Cb 

2.70 

3-35 

4.04 

XP 

La 

2.25 

3.OO 

3-75 

— 0.75  11 

XP 

2.00 

2  CO 

—0.50  n 

XP 

ab 

1. 00 

I. 00 

1. 00 

+  1.00 

XP 

be 

1.25 

1.41 

I,60 

— 0.25^2+ !6 

XP 

PRATT  TRUSS,  TWELVE  PANELS. 


Member 

ft=3 

n=4 

General  Formulas. 

1 2 .  <o 

14.81 

+  2.75^+4 

XP 

Da 

9,01 

1 1 . 1 0 

13.46 

XP 

Ei 

5.1  I 

10. 06 

12.12 

+  2.2  5  vV  i_4 

XP 

Fh 

7.21 

8.04 

IO.77 

-'-2.00v/«2_L  ^ 

X  r 

Gk 

6.31 

7.83 

9.42 

+  «2+4 

X  r 

La 

8.25 

1 1. 00 

I3.75 

— 2.75^ 

XP 

Lc 

7.50 

10.00 

12.50 

— 2.50/7 

XP 

Le 

6.75 

9.00 

II.25 

— 2.25« 

XP 

Lg 

6.00 

8.00 

10.00 

— 2.00ft 

XP 

Li 

5.25 

7.00 

8.75 

—  1.75^ 

XP 

LI 

4.50 

6. co 

7.50 

—  1. 50ft 

XP 

ab 

i  .00 

1. 00 

1. 00 

+  1.00 

XP 

cd 

1.50 

1.50 

1.50 

+1.50 

XP 

ef 

2.00 

2.00 

2.00 

4-2.00 

XP 

gh 

2.50 

2.50 

2.5O 

+2.50 

X  P 

ik 

3.00 

3.00 

3  00 

+  3 -co 

xP 

be 

1.25 

1.41 

1.60 

—0.25^+16 

XP 

de 

1.68 

1.80 

1.95 

—0.25^^+36 

xP 

fg 

2.14 

?  14 
— . — -j. 

2.36 

—0  2  5%/;/2  +  54 

xP 

hi 

2.61 

2.69 

2.80 

— 0.2  5v/^2-|-iOO 

xP 

kt 

3.09 

3.16 

3,25 

— <3.2$V  ?/2-fl44 

XP 

12 


PRATT   TRUSS,    SIX  PANELS. 


Member 

n=4 

n=$ 

General  Formulae. 

Ba-Cb 

A  CI 

C  CO 

-K.25.vV  -f-4 

XP 

Dd 

3.61 

+  i.oovV  4-  4 

XP 

La 

J*/ > 

5  «oo 

6.25 

— 1.25  ft 

XP 

Lc 

3-00 

a  on 

5 .00 

— 1. 00  n 

XP 

Lc 

2.25 

3.00 

3-75 

— 0.75  ft 

XP 

ab 

1. 00 

1,00 

LOO* 

+  1.00 

XP 

cd 

1.50 

1.50 

1,50 

+  1.50 

XP 

be 

1.25 

1,41 

1.60 

— 0.25^:4- 

XP 

de 

1.68 

1.80 

1.95 

— 0.25v/^2_j-  36 

XP 

PRATT    TRUSS,    TEN  PANELS. 

Member 

n=$ 

n=$ 

General  Formulas. 

Ba-Cb 

8.ii 

10.06 

12.12 

+  2.25s/^2_L.4 

XP 

Dd 

7.21 

8.94 

10.77 

+  2.00%/^-L.4 

XP 

Ef 

6.31 

7.83 

9.42 

+  I-75  vV+4 

XP 

Fh 

5.41 

6.71 

8.08 

4-1.50^+4 

XP 

La 

6.75 

9.00 

11.25 

— 2.257* 

XP 

Lc 

6.00 

8.00 

10.00 

— 2.00ft 

XP 

Le 

-  5.25 

7.00 

8.75 

—1.757* 

XP 

Lg 

4.50 

6.00 

7.50 

— 1.50ft 

XP 

Li 

3.75 

5.00 

6.25 

— 1.25ft 

XP 

ab 

i  .00 

1. 00 

1. 00 

+  1.00 

XP 

cd 

1.50 

1.50 

1.50 

+  1.50 

XP 

ef 

2.00 

2.00 

2.00 

+  2. CO 

XP 

gh 

2.50 

2.50 

2.50 

+2.50 

XP 

be 

1.25 

1.41 

1.60 

— o-25\/ft-+i6 

XP 

de 

1.68 

1.80 

1.95 

—0.25^24.36 

XP 

fg 

2.14 

2.24 

2.36 

— 0.25v/w2+64 

XP 

hi 

2.61 

2.69 

2.80 

—0.25^^-!  00 

XP 

COEFFICIENTS   FOR   ROOF  TRUSSES.  13 


i  


s  =  span,  h  ==  height.  P  =  panel  load,  n  = £  =  piJch  -{-  compressions  — tension. 
Strain  in  member  =  P  X  coefficient.    Load  on  wall  or  column^  Reaction  -  I-0.5  P 

COMPOUND  FINK  TRUSS. 


Member. 

0=3 

«=4 

General  Formulae. 

Ba 

6.31 

7-83 

9.42 

~Hl/  ^2  +  4 

XP 

La 

5-25 

7.00 

875 

— in 

XP 

ab 

0.83 

0.89 

o-93 

n 

1 

XP 

Cb 

576 

7-38 

9-05 

+✓#.+4  (|W2  +  5) 

XP 

be 

o-75 

1. 00 

1.25 

— \n 

XP 

Lc 

4-50 

6.00 

7-50 

—  In  ■ 

XP 

cd 

1.66 

1.79 

1.86 

XP 

De 

5.20 

6-93 

8.68 

XP 

ed 

1. 00 

1-25 

-\n 

XP 

3.00 

4.00 

5.00 

—  n 

XP 

I?  59 

2.00 

2.50 

—\n 

XP 

ef 

0.83 

0.89 

o.93 

n 

1/^2  +  4 

XP 

fe 

2.25 

3.00 

375 

XP 

Ef 

4-65 

6.48 

8.31 

+  T/,2+4(^  +  l) 

XP 

i4 


SIMPLE  FINK  TRUSS. 


Member. 

*  71  =  f 

=  \ 

Ba 

2.71 

3-35 

La 

2.25 

3.00 

ab 

0.8? 

0.89 

Cb 

2.15 

2*91 

be 

0-75 

1. 00 

Lc 

I.50 

2.00 

«=5 


4.04 
3-75 

o.93 

3.66 

j.25 

2.50 


General  Formulae. 


+ 


V  n2  +  4 


XP 
XP 

XP 


Vn2  +  4 


-J4* 


4  ^ 


XP 

XP 
XP 


COMPOUND  FAN  TRUSS. 


Member. 

n=2> 

4 

Ba 

9.91 

12.30 

14.80 

La 

8.25 

11.00 

I3-75 

ab-bc 

0.93 

1  1.08 

1. 21 

Cb 

8.94 

11.25 

13.66 

Dc 

8.80 

11.40 

14.07 

cd 

1.50 

2.00 

2.50 

Ld 

6.75 

9,00 

11,25 

de 

2.69 

2.79 

Ef 

8.25 

10.96 

13.69 

fe 

1.50 

2.00 

2.50 

ei 

2.25 

3.00 

3-75 

Li 

4-5o 

6.00 

7-5° 

fg-gb 

°-93 

1.08 

1. 21 

% 

7.28 

9-93 

12.54 

Gh 

7-H 

10.06 

12.95 

hi 

3-75 

5.00 

6.25 

General  Formulae. 


—H-n    XP 

;/4-}-40^2  +  i44  xp 
6  (#24-4) 

(tf**+Sf)  xp 


n  i/«2+4 


1/  «2+4 


2' 


+ 


3« 


1/  ^2-4-4 


l/«2  +  4 

— 


(-V-^2+7)  XP 

XP 
XP 

XP 

.(¥>*2  +  5)  XP 

XP 
XP 
XP 


■^i/nA+ 4DH2  +  144  xp 
6  (^2+4) 

(tt»2+3)  XP 


$  l/^2-f-4 
1 


1  y  ^24-4 
— \n 


(V#»+x)i  XP 
XP 


SIMPLE  FAN  TRUSS. 


15 


Member. 


Ba 


La 

ab 
be 


Cb 

Dc 

cd 
Ld 


1/7=3 


4-5° 
375 
0-93 

3  53 

3-39 

1.50 
2.25 


w=4 


5-59 
5.00 

1.08 

4.55 

4.70 

2.00 
3.00 


;/=5 


673 
6.25 

1. 21 
5.58 

5.98 
2.50 
375 


General  Formulae. 


J/«2  +  4 

in 


02  +  5) 


XP 


4-  nv  7U  -f40^+ 144  x  p 

6  (?22  +  4)" 


+ 


(.U;22-L^  XP 


Vn*  +4 


-tin 


($**-fl)  XP 

XP 
XP 


STEEL  COLUMN  UNIT.  STRAINS.    □  □  12500  -  500 


□  □ 

0  □ 

□  □ 

f  □  □ 

3-o  . 

irooo 

7.6 

8700 

12.2 

6400  . 

16.8 

4100 

.2 

10900 

.8 

8600 

.4 

6300 

17.0 

4000 

4 

10800 

8.0 

8500 

.6 

6200" 

.2 

3900 

.6 

10700 

.2. 

8400 

..8 

6100 

.4 

3800 

.8 

10600 

.4 

8300 

13.0 

6000 

.6 

3700 

4.0 

10500 

.6 

8200 

.2 

5900 

.8 

3600 

.2 

10400 

.8 

8100 

•4 

5800 

18.0 

35oo 

•4 

10300 

9.0 

8000 

.6 

5700 

.2 

3400 

.6 

10200 

.2 

7900 

.8 

5600 

•4 

3300 

.8 

IOIOO 

•4 

7800 

T4.o 

55oo 

.6 

3200 

10000 

.6 

7700 

.2 

5400 

.8 

3100 

.2 

9900 

;8 

7600 

•4 

53oo 

19.0, 

3000 

•4 

9800 

IOiO 

7500 

.6 

5200. 

2 

2900 

.6 

9700 

.2 

7400 

.8 

5100 

•4 

2800 

.8 

9600 

.4 

7300 

15.0 

5000 

.6 

2700 

6.0 

9500 

.6. 

7200 

.2 

4900 

.8 

2600 

.2 

9400 

.8 

'7100 

•4 

4800 

20.0 

2500 

•4 

9300 

11. 0 

7000 

.6 

4700 

.2 

2400 

.6 

9200 

.2 

6900 

.8 
16.0 

4600 

.4 

2300 

8 

9100 

•4 

6800 

'4500 

.6 

2200 

7.0 

9000 

.6 

6700 

'.2 

4400 

.8 

2100 

.2 

8900 

.8 

6600 

•4 

4300 

•4 

8800 

11. 0 

6500 

.6 

4200 

SHEARING  AND  BEARING  VALUE  OF  RIVETS. 


Diam.ofRivet 
in  inches. 

Area  of 
Rivet. 

Single 
Shear at 
10000  ft 
pr  eq  in 

Bearing  val.  of  different  thicknesses  of  plato  at  2Q000  lbs.  per  sq.  in. 
(  =  Diam.  of  Rivet  X  thickness  of  plate  X  20000  lbs. 

Frac- 
tion. 

.  Eteci- 
mal. 

i// 

4 

f" 

9  // 
T6 

5// 

1  I// 

¥' 
A" 
t" 

•5 

•5625 
.625 

•1963 
-2485 
.3068 

i960 
2480 
3070 

'  250O 
28TO 

„3i30M 

3130 
352o 
39io 

3750 
4210 
4690 

4920 
5470 

1 1// 

3  // 

\¥' 
1" 
if" 

.6875 
•75  ; 
8125 

.875 
•9375 

.3712 
,.4418 
.5185 
.6or3 
.6903 

37IO 
4420 
5l8o 
6010 
6900 

$440 
3750 
4070 
4380 
4690 

4290 
4690 

5160 
5630 
6090 
6570 
7030 

6010 
6560 
7110 
7660 
8200 

6880 
7500 
812a 
8750 
9370 

8440 
9150 
984O 
I0550 

IOI60 
IQ.94O 
I I72O 

I289O 

5080 
5470 
5850 

INDEX. 


Acceptance,  72,  95. 
Architect,  72,  91,  95. 
Anchors,  54. 

Bars,  13,41,63,  77,78,  79, 

80,  81,85,  87, 88. 
Battens,  60. 
Bessemer  Steel,  82. 
Bearing,  18,  53, 65. 
Beams,  13. 

Bending,  16,  19,  52,62,86, 
Bed  Plates,  53. 
Boards,  6. 
Bolts,  21,  54. 
Built  Members,  69. 

Clips,  31,  47. 

Corrosion,  10. 

Columns,  14,  42,  44. 

Compression  Members,  14, 
24,  43,  44,  45,  52,  58, 
59,  60,  61,  65,  66,  69. 

Completion,  95. 

Combined  Strains,  16. 

Corrugated  Iron,  8,  26,27, 
28,  31,  32,  33-,  89,  91, 

Contractor,  72, 93,  94. 

Damage,  92,  93,  94,  95, 
Drawings,  1,  2,  72. 
Decisions,  72. 
Diagram,  1,  2,  72. 
Dimensions,  3,  23. 
Drift  Pins,  70,  71. 

Elastic  Limit,  76,  87,  88. 
Erection,  41,  51,  90,  91,92, 
■     93, 94,  95- 
Engineer,  72,  91,  92,93,94. 
^,  95- 

Elongation,  77,  78,  87,  88, 

Falsework,  92. 
Framing,  89. 
Flanges,  13,  15,  24. 
Flashing,  29. 
Field  Connections,  21. 
Finish  Angle,  33. 
Finished  Surfaces,  65. 
Foundations,  3,  52,  53, 54. 
Foundries,  34. 

Girders,  13,  15,  17,  23, 
24,  25. 


Imperfections,  73,  85. 

Joints,  24,  38,  65. 

Lacing,  60,  61,  62. 
Lap,  28. 

Laterals,  13,  20,  41. 
Lateral  Connections,20, 
4i. 

Lighting,  35,  36.. 
Loads, 5,6,7,8,9,10,1 1, 12 
Louvres,  34. 

Machinery,  11. 
Machine  Shops,n, 34,35. 
Main  Members,39,43,44- 
Masonry,  3,  52,  53,  54. 
Mill  Buildings,  10,  11, 

34,  35- 
Minimum  Loads,  10,  11. 
12. 

Offsetting,  86. 

Open  Hearth  Steel,  82. 

Plate  Iron.  87,  88. 
Painting,  66,  90,  91. 
Planing,  65,  66,89. 
Plaster,  8. 

Plate  Girders,  13,  15,17, 

23,  24,  25. 
Pitch  Roof,  4,  5->6. 
Pitch  Rivets,  58, 
Pins,  17,  18,  19. 
Process  of  Manuf'g-,  74, 

82. 

Phosphorus,  86. 
Punching,  55,  56,  57,  58. 
Purlins,  8,  19,  22,  31,46, 

47,  48,  49,  50. 
Purlin  Spacing,  27,  48. 
Purlin  Clips,  31,  47* 

Rafters,  43. 
Reaming*  56,  71. 
Redress,  72. 

Rivets,  17,  18,55,  56,  57, 
58,  67,  68,  69. 

Rivet  Holes,  55,  56,  57, 
67,  68. 

Ridges,  30, 

Risks,  93. 

Roll  Cap,  30. 

Rollers,  53^ 


Sways,  41,  51,  52. 
Span,  23,  27,  46. 
Strain  Sheet,  1,  2,  72. 
Slate,  8. 

Shapes,  13,  87,  88. 
Sag  Ties,  42. 
Secondary  Members,  40, 

44,  45. 
Sheeting,  8. 
Shearing,  17. 
Screw,  63. 

Steel,  82,  83,  84,  85,  86, 

87,88, 
Stiffeners,  25. 
Splices,  24,  38,  65,  67. 
Snow,  34. 
Snow  Load,  5. 
Soft  Steel,  86,  87. 
Soft-Medium  Steel,  86, 

88. 

Sub-Struts,  44,  45. 
Sulphur,  86. 
Skylights,  36. 

Test  Pieces,  75,  83,  84. 

Tension  Members,  13, 
16,  24,  37,  38,  39, 
40,  41,42,  57,  68. 

Timber,  22,  50. 

Tie  Plates,  60. 

Tools,  92. 

Trusses,  9,  46. 

Turning,  66,  89. 

Upsets.  63. 

Unit  Strains,  13,  14,  15, 
16,  17,  18,  19,  20, 
21,  22,  59. 

Valleys,  29. 

Variation  in  Weight,  64. 
Ventilation,  34. 

Water,  29;  34. 
Webs,  17,  24,  43,  62. 
Weight  Alaterial,  64. 
Weight  of  Trusses,  9. 
Wind,  6,  7. 
Windows,  35. 
Wrought  Iron,  73,  74, 

75,  76,. 77,  78,  79, 

80,  81. 


